Poor communication often appears at the top of contributing and causal factors in accident reports, and is therefore one of the most critical human factor elements. Communication refers to the transmitter and the receiver, as well as the method of transmission. Transmitted instructions may be unclear or inaccessible. The receiver may make assumptions about the meaning of these instructions, and the transmitter may assume that the message has been received and understood. With verbal communication it is common that only 30% of a message is received and understood.
Detailed information must be passed before, during and after any task, and especially across the handover of shifts. Therefore, when messages are complex they should be written down, and organisations should encourage full use of logbooks, worksheets, and checklists etc. Verbal messages can be kept short, with the most critical elements emphasised at the beginning and repeated at the end. Assumptions should be avoided and opportunities for asking questions both given and taken.